Electrical energy is often generated by power stations that are located several miles away from where the electrical energy is consumed. This locational mismatch between electrical energy generation and electrical energy consumption can lead to some logistical challenges arising when it comes to distributing the generated electrical energy. To further complicate the problem, more electrical energy is typically consumed at specific hours during the day, which are referred to as peak hours. Peak hours are, for example, when high energy appliances such as heaters or air conditioning units are required by multiple consumers at the same time.
The energy demand at peak times leads to a strain on both the power stations attempting to generate the necessary quantity of electrical energy and the distribution networks attempting to deliver the generated energy to the consumers from the power stations. The cost of generating electrical energy at peak times increases due to operating power stations in a less efficient regime in order to generate more power.
Using the current power generation and distribution network topologies, significant investments must be made in both electrical energy generation and distribution capabilities, in order to keep pace with the ever increasing energy demand. However, despite the strenuous demands placed on power stations and distribution networks at peak times, the same power stations are underutilised during periods of low demand. This fluctuation in demand can be especially problematic for fuel-based power plants, which are more easily and efficiently operated at a constant electrical energy production level. It is therefore not economical to build more power stations to cope with the peak demand, when the power stations are only fully utilized for a small number of hours per day. It is rational however, to suggest that energy could be produced and stored during the time periods in which the existing power stations are underutilized. Localising this stored energy to a power station or purpose built commercial power bank does not alleviate the strain placed upon the power distribution network during peak times. Hence, the pragmatic approach to alleviating the peak demand placed upon power stations is to both generate and distribute energy during off-peak hours and then use the pre-distributed stored energy during peak periods to alleviate the strain placed upon power stations and the distribution network during peak periods. This method would however rely on end users installing relatively expensive energy storage, which may not be desirable.
Energy storage has the potential to dramatically change the challenges associated with peak time energy generations and delivery. Utilising energy sources integrated with other hardware enables distributed energy sources to be introduced to the end users whilst minimising impact on expenditure. Distributed energy sources are gaining momentum and playing an essential role in the process of improving the reliability of electrical systems and reducing the peak load placed on power generation and distribution systems through the use of smart load management.
Although stored electrical energy is recovered in a direct current format, mains electricity is distributed and consumed in an alternating current format. The alternating current format is utilised for mains electricity because it is more convenient to transport and it is the format in which electrical energy is inherently recovered from a generator. The issue of power conversion is relatively trivial. The implementation of a mains inverter allows the stored DC electrical energy to be converted into an AC format suitable for mains powered devices.
Electrical energy providers have a vested interest in reducing the peak load placed upon power generation and distribution systems. They have attempted to mitigate the problem through the use of demand side management incentives, for example, by offering lower cost energy during off peak periods or by offering to pay a feed in tariff for supplemental electrical energy provided to the supplier during peak periods; these schemes envisage successful power management being obtained through altering consumer behaviour. One of the main goals of demand side management is to enable the price of electricity to be set dynamically based on the cost of electricity generation at a given time. Dynamic pricing would theoretically give rise to a supply and demand scenario and hence lead to a reduction in peak energy consumption, although it is unlikely to be a scheme readily adopted by end users.
The implementation of smart load management is the critical next step in helping consumers to take advantage of the favourable off-peak energy rates, without incurring the increased cost of electricity at peak times or sacrificing the use of utilities. Driving circuits capable of utilising distributed energy storage for demand side management facilitate the consumer in reducing their real time energy demand and energy cost as well as concurrently providing an emergency backup system for providing energy to critical facilities, such as lighting, in the event of a power cut.
Driving circuits controlling current distributed energy storage systems are able to provide peak load management by ending the charge cycle during peak periods and using the energy stored to power an attached appliance. This system works sufficiently to power the attached appliance, but it does not fully utilise the stored power in all circumstances. For example, if there is more stored energy than is required by the attached appliance then the stored energy will not be used in the most effective manner to reduce the peak load placed upon power stations and the energy distribution network.